The last line of my VB6 post post was this: "Commercial vendors, particularly, have no legal obligation to their customers." To clarify this, companies are legally obligated to their owners, not their customers. Since the owners own the company and have their investment at risk, the company has to act in their interest... even if it's in opposition to their customer's interest.
Since a company has to have customers to survive, most of the time the interests of the owners are in line with the interests of the customers. However, this isn't always the case: Microsoft's VB6/VB.Net decision might be an example. If you believe that the lower costs and better prospects of VB.Net outweigh the lost goodwill of all those VB6 developers, then you can also argue that dumping VB6 was a net profitable thing to do. This is despite the fact that so many customers are paying a price for the decision.
So... if you're a VB6 developer and you're upset about the way you were treated, the best protest you can make is to make Microsoft's decision a bad one. Make it unprofitable. When it comes time to pick a replacement platform, vote with your wallets and send your dollars somewhere else (and hopefully to a platform served by more than one vendor).